Flow valve

Abstract

A flow valve comprising two valve members having contacting flat surfaces, one of the members containing spaced inlet and outlet fluid passages and the other of the valve members containing an intermediate passage, the valve members being mounted such that relative rotation of the flat surfaces can be effected to locate the intermediate passage either fully or partially in or out of communication with the inlet and outlet passages, and a channel is provided around at least part of the periphery of the contacting flat surfaces to receive molten metal and dross leaked between them.

We claim: 
     
       1. A flow valve for controlling molten metal flow comprising first and second valve member having contacting flat surfaces with peripheries, said first valve member containing spaced inlet and outlet fluid passages and said second valve ember containing an intermediate passage for simultaneously communicating with both said inlet and outlet passages in said first valve member, said first and second valve member being mounted such that relative rotation of the flat surfaces can be effected to locate said intermediate passage either fully or partially in or out of communication with said inlet and outlet passages, and including a channel around at least part of the peripheries of said contacting flat surfaces to receive molten metal and dross leaked between them. 
     
     
       2. A flow valve as claimed in claim 1, wherein said channel extends completely around the peripheries of the contacting flat surfaces. 
     
     
       3. A flow valve as claimed in claim 1, wherein said first and second valve members are located in a housing, and wherein said channel is in the form of a groove or recess in said housing. 
     
     
       4. A flow valve as claimed in claim 1, wherein said channel extends below a plane of contact of the flat surfaces of said valve members. 
     
     
       5. A flow valve as claimed in claim 1, wherein said housing includes at least one leak port for removal of material received by said channel. 
     
     
       6. A flow valve as claimed in claim 5 wherein said at least one leak port slopes downwardly. 
     
     
       7. A flow valve as claimed in claim 1 wherein the flat surfaces of the valve members each have a carbide coating. 
     
     
       8. A flow valve as claimed in claim 7 wherein the carbide coating of each surface has a surface flatness of not more than 3 light bands. 
     
     
       9. A flow valve as claimed in claim 1, including a spring acting on one of said first and second valve members to bias said flat surfaces into contact. 
     
     
       10. A flow valve as claimed in claim 9, wherein said spring is a disc spring or a coil spring. 
     
     
       11. A flow valve as claimed in claim 1, wherein at least one of the inlet, outlet and intermediate passages is adapted to receive an orifice plate to control an effective diameter thereof.